Conformational control in the synthesis of mixed tetraethers of calix[4]arene

✍ Scribed by Miguel Pitarch; Julie K. Browne; Michael A. McKervey

• Book ID: 104207946
• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 596 KB
• Volume: 53
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(97)00661-3

✦ Synopsis

A series of mixed tetraethers of ealix [4]arene in which two distal substituents are methyl acetates and the other two are 1-aikenyl groups with 3-6 carbon atoms in the chain have been prepared by two mutes which differ in the order in which the group (methyl acetate or alkenyl) were introduced. The fmal eonformational outcome depends on which group was introduced fwst. Cone (major) and 1,3-alternate (minor) conformers resulted when the alkenyi groups were introduced first. When the order was reversed, only partial cone conformers were produced. Formation of cone/1,3-alternate conformers via one route and partial cone conformers by the alternative route may be explained on the basis of a template effect operating at the fourth alkylation stage and involving the sodium counterion of the base.